This project seeks to develop both fundamental understanding and new technology to accelerate the efficient and cost-effective harvesting of waste heat in automotive exhaust systems.

Intellectual Merit: Scientific issues to be addressed include thermoelectric materials development, advanced systems-level thermal management and design, heat sink design, development of novel thermal interface materials, and advanced metrology for material and system assessment. Thermoelectric materials to be investigated include filled-skutterudites that are currently being investigated by the corporate partner, General Motors, as well as nanowire-based materials, nanocrystalline ceramic compounds, and metal/conductor superlattices to be developed at Purdue. Systems-level thermal modeling will be conducted to maximize the temperature difference across the thermoelectric material, thereby increasing the efficiency with which waste heat can be converted to electric power. Novel durable nanoscale thermal interface materials will be developed to minimize thermal resistances in order to promote high energy conversion efficiency.. Properties will be measured using a photoacoustic method and a laser thermal reflectance method at Purdue in conjunction with use of facilities at the Oak Ridge National Laboratory.

Broader Impact: The collaboration between researchers at Purdue and General Motors will accelerate the development of new technology that will promote the efficient and cost-effective thermoelectric conversion of waste heat to electric power in vehicle applications. Successful development and ultimate implementation will improve fuel economy and reduce emissions. The research results will be disseminated by traditional means, as well as through Purdue?s nanoHUB and thermalHUB web portals. The research will provide graduate students with interdisciplinary research experiences, as well as industrial experience through internships in industry. The research will be integrated with undergraduate and graduate courses and serve as the basis for undergraduate design projects. Outreach activities to high school students, including students from underrepresented groups, have been planned.

Project Report

This research project is in collaboration with the General Motors Global R&D (GM) to enable ultimately the broad adoption of thermoelectric (TE) waste heat recovery systems, or TE generators (TEG), at a scale commensurate with the global vehicle manufacturing enterprise. We exploit the complementary missions of research/development at Purdue and deployment/commercialization at GM to develop the fundamental understanding and technology improvements needed to make viable the efficient conversion of waste heat in automotive exhaust systems to electricity. We address the key elements for the development and deployment of commercial automotive TEGs. The specific research activities are: (1) TE materials development, including (a) understanding the performance of skutterudites that are used as the TE material at GM, (b) development of nanowire based TE materials, (c) development of metal-semiconductor superlattice thermoelectrics. (2) Development of efficient heat exchanger and system level thermal modeling of the TEG. (3) Thermal interface materials development. (4) Metrology tool development. This project has successfully accomplished the research objectives and beyond. We have (1) Investigated TE performance of skutterudites with different filling methods. The study provided insights for improving properties of TE materials. (2) Designed and optimized new thermoelectric generators. (3) Designed and built a test bench for TEG bench testing. (4) Grew PbTe, Bi2Te3, and Ag2Te nanowires in large quantities (>10 g/batch), synthesized and evaluated PbTe-Bi­2Te3 and PbTe-Ag2Te nanowire heterostructures, and tested a thin film thermoelectric device. (5) Discovered extraordinarily interface thermal conductance in superlattice TE materials. (6) Designed and assembled a test bench for thermal interface materials and successfully characterized thermal interfaces. This project provided trainings to 8 graduate students and 3 undergraduate students in a broad field of thermal science, system engineering, materials, and characterization, increased participation of students from underrepresented groups, and carries out outreach activities to high school students. At the conclusion of the project, we are continuing our collaborations with GM and contributing to their development of TEGs. GM has built a TEG that has been tested at Purdue, and a modified TEG is being built and will be evaluated for laboratory tests at Purdue as well as road tests. We believe implementation of thermoelectrics for automobile waste heat recovery will reduce energy/oil consumption, reduce environmental pollution, and reduce the reliance of energy on foreign sources, therefore, will have significant impact to the society.

Project Start
Project End
Budget Start
2011-01-01
Budget End
2014-12-31
Support Year
Fiscal Year
2010
Total Cost
$1,391,825
Indirect Cost
Name
Purdue University
Department
Type
DUNS #
City
West Lafayette
State
IN
Country
United States
Zip Code
47907